How many moles of H3O+ or OH- must you add per liter of HA solution to adjust its pH from 4.52 to 5.25? Assume?

Question

How many moles of H3O+ or OH- must you add per liter of HA solution to adjust its pH from 4.52 to 5.25? Assume a negligible volume change.
Please explain!
Thanks!

Answer 1

Best Answer - Chosen by Asker

look at he concentrations of H3O+ ions in both solutions

pH 4.52 [H3O+]=10^-4.52=3.02*10^-5M

pH 5.25 [H3O+]=10^-5.25=5.62*10^-6M

So to go to 3.20*10^-5M to 5.62*10^-6M , you must neutralize some H3O+ ions adding OH- ions in concentrations
3.02*10^-5 - 5.62*10^-6=2.46*10^-5M of ions OH-

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Thanks!